Report: In-app purchases a strong source of iOS app revenue

iOS app developers who are looking to make big bucks on the App Store should consider using the in-app purchase model, according to a recently published study from Distimo. In-app purchases are a huge source of revenue, accounting for a whopping 72 percent of all App Store revenues.

That number has increased drastically from July of 2010, when only 28 percent of App Store revenues came from in-app purchases. What's even more surprising is that only four percent of all apps are currently using the in-app purchase model.

This all points to a trend of freemium apps dominating the App Store. These, of course, are apps that are free to download and try out, but require an in-app purchase to supply full functionality. Freemium apps made up the majority of the revenue -- 48 percent, or nearly half of all App Store earnings. Many of these apps are games, but comic apps are also starting to create an impact.

TUAW would like to know what your favorite purchase model is -- a one-time purchase that gives you unlimited upgrades and full functionality, or a free download with in-app purchases. Answer our poll below, and if you feel compelled to provide a longer answer, do so in the comments.